This application to the RFA-AT-19-006 HEAL Initiative: Behavioral Research to Improve MAT: Behavioral and Social Interventions to Improve Adherence to Medication Assisted Treatment for Opioid Use Disorders (R61/R33 Clinical Trial Optional) will develop and execute a Sequential Multiple Assignment Randomized Trial (SMART) Design to test two forms of behavioral economics intervention to promote Medication Assisted Treatment (MAT) for Opioid Use Disorder. The R61 phase will collect qualitative and quantitative data from existing buprenorphine-naloxone patients to explore modifiable factors that may impact MAT adherence. This information will be used to adapt an in person, brief motivational interviewing and substance free activities intervention (BMI+SFAS) previously developed to reduce binge/problematic drinking and marijuana use. This BMI+SFAS will be compared with contingency management, one of the most effective forms of psychosocial treatment for substance use. After the development phase, both forms of intervention will be tested for satisfaction and acceptability with participants who are initiating buprenorphine-naloxone treatment. Feasibility of methods will also be assessed during this pilot to identify any issues with execution. The R33 phase of this application will execute a Sequential Multiple Assignment Randomized Trial (SMART) to test these two different forms of intervention to promote MAT adherence during the four weeks of treatment initiation, and throughout the following 6 months of MAT. Adherence to buprenorphine-naloxone will be defined as attendance at physician visits, a positive urine screen for buprenorphine-naloxone, and prescription drug monitoring. After the first randomization, we predict that a higher percentage of those in the contingency management condition will be adherent than those in BMI+SFAS. Those who are adherent throughout the first 4 weeks will continue in their arm of intervention for the next 6 months, but those non-adherent with be re- randomized to either switch to the other form of intervention or add the other form of intervention. Adherence will then be assessed again after 6 months of intervention. This innovative design that tests the sequential use of two psychosocial interventions to increase adherence to MAT initiation is likely to have a significant impact on engagement of Opioid Use Disorder patients in treatment. The use of a SMART design will test multiple levels of intervention for individuals who are resistant to MAT adherence, therefore addressing an underserved population with Opioid Use Disorder.